Fix event path iteration

Instead of shoehorning all target handling into the bubbling iteration, this separates "capturing" iteration from "bubbling" iteration and the Event object's phase is set to target as appropriate in both.

This also invokes the event listeners in a more natural order.

Tests: web-platform-tests/wpt#13030 & web-platform-tests/wpt#13031.

Fixes #685.

Author: annevk

dom.bs

@@ -1385,22 +1385,28 @@ for discussion).
    <var>clearTargetsStruct</var>'s <a for=Event/path>touch target list</a> is a <a for=/>node</a>
    and its <a for=tree>root</a> is a <a for=/>shadow root</a>, and false otherwise.
 
-   <li><p>Set <var>event</var>'s {{Event/eventPhase}} attribute to {{Event/CAPTURING_PHASE}}.
-
    <li><p>If <var>activationTarget</var> is non-null and <var>activationTarget</var> has
    <a for=EventTarget>legacy-pre-activation behavior</a>, then run <var>activationTarget</var>'s
    <a for=EventTarget>legacy-pre-activation behavior</a>.
 
    <li>
-    <p>For each <var>struct</var> in <var>event</var>'s <a for=Event>path</a>, in reverse order:
+    <p><a for=list>For each</a> <var>struct</var> in <var>event</var>'s <a for=Event>path</a>, in
+    reverse order:
 
     <ol>
-     <li><p>If <var>struct</var>'s <a for=Event/path>target</a> is null, then <a>invoke</a> with
-     <var>struct</var>, <var>event</var>, and <var>legacyOutputDidListenersThrowFlag</var> if given.
+     <li><p>If <var>struct</var>'s <a for=Event/path>target</a> is non-null, then set
+     <var>event</var>'s {{Event/eventPhase}} attribute to {{Event/AT_TARGET}}.
+
+     <li><p>Otherwise, set <var>event</var>'s {{Event/eventPhase}} attribute to
+     {{Event/CAPTURING_PHASE}}.
+
+     <li><p><a>Invoke</a> with <var>struct</var>, <var>event</var>, "<code>capturing</code>", and
+     <var>legacyOutputDidListenersThrowFlag</var> if given.
     </ol>
 
    <li>
-    <p>For each <var>struct</var> in <var>event</var>'s <a for=Event>path</a>, in order:
+    <p>If <var>event</var>'s {{Event/bubbles}} attribute is true, then <a for=list>for each</a>
+    <var>struct</var> in <var>event</var>'s <a for=Event>path</a>:
 
     <ol>
      <li><p>If <var>struct</var>'s <a for=Event/path>target</a> is non-null, then set
@@ -1409,10 +1415,8 @@ for discussion).
      <li><p>Otherwise, set <var>event</var>'s {{Event/eventPhase}} attribute to
      {{Event/BUBBLING_PHASE}}.
 
-     <li><p>If either <var>event</var>'s {{Event/eventPhase}} attribute is {{Event/BUBBLING_PHASE}}
-     and <var>event</var>'s {{Event/bubbles}} attribute is true or <var>event</var>'s
-     {{Event/eventPhase}} attribute is {{Event/AT_TARGET}}, then <a>invoke</a> with
-     <var>struct</var>, <var>event</var>, and <var>legacyOutputDidListenersThrowFlag</var> if given.
+     <li><p><a>Invoke</a> with <var>struct</var>, <var>event</var>, "<code>bubbling</code>", and
+     <var>legacyOutputDidListenersThrowFlag</var> if given.
     </ol>
   </ol>
 
@@ -1476,7 +1480,8 @@ for discussion).
 </ol>
 
 <p>To <dfn noexport id=concept-event-listener-invoke>invoke</dfn>, given a <var>struct</var>,
-<var>event</var>, and an optional <var>legacyOutputDidListenersThrowFlag</var>, run these steps:
+<var>event</var>, <var>phase</var>, and an optional <var>legacyOutputDidListenersThrowFlag</var>,
+run these steps:
 
 <ol>
  <li><p>Set <var>event</var>'s <a for=Event>target</a> to the <a for=Event/path>target</a> of the
@@ -1502,7 +1507,7 @@ for discussion).
   run. Note that removal still has an effect due to the <a for="event listener">removed</a> field.
 
  <li><p>Let <var>found</var> be the result of running <a>inner invoke</a> with <var>event</var>,
- <var>listeners</var>, and <var>legacyOutputDidListenersThrowFlag</var> if given.
+ <var>listeners</var>, <var>phase</var>, and <var>legacyOutputDidListenersThrowFlag</var> if given.
 
  <li>
   <p>If <var>found</var> is false and <var>event</var>'s {{Event/isTrusted}} attribute is true,
@@ -1526,15 +1531,15 @@ for discussion).
       <tr><td>"<code>transitionend</code>"<td>"<code>webkitTransitionEnd</code>"
     </table>
 
-   <li><p><a>Inner invoke</a> with <var>event</var>, <var>listeners</var>, and
+   <li><p><a>Inner invoke</a> with <var>event</var>, <var>listeners</var>, <var>phase</var>, and
    <var>legacyOutputDidListenersThrowFlag</var> if given.
 
    <li><p>Set <var>event</var>'s {{Event/type}} attribute value to <var>originalEventType</var>.
   </ol>
 </ol>
 
 <p>To <dfn noexport id=concept-event-listener-inner-invoke>inner invoke</dfn>, given an
-<var>event</var>, <var>listeners</var>, and an optional
+<var>event</var>, <var>listeners</var>, <var>phase</var>, and an optional
 <var>legacyOutputDidListenersThrowFlag</var>, run these steps:
 
 <ol>
@@ -1550,13 +1555,11 @@ for discussion).
 
    <li><p>Set <var>found</var> to true.
 
-   <li><p>If <var>event</var>'s {{Event/eventPhase}} attribute value is {{Event/CAPTURING_PHASE}}
-   and <var>listener</var>'s <a for="event listener">capture</a> is false, then
-   <a for=iteration>continue</a>.
+   <li><p>If <var>phase</var> is "<code>capturing</code>" and <var>listener</var>'s
+   <a for="event listener">capture</a> is false, then <a for=iteration>continue</a>.
 
-   <li><p>If <var>event</var>'s {{Event/eventPhase}} attribute value is {{Event/BUBBLING_PHASE}} and
-   <var>listener</var>'s <a for="event listener">capture</a> is true, then
-   <a for=iteration>continue</a>.
+   <li><p>If <var>phase</var> is "<code>bubbling</code>" and <var>listener</var>'s
+   <a for="event listener">capture</a> is true, then <a for=iteration>continue</a>.
 
    <li><p>If <var>listener</var>'s <a for="event listener">once</a> is true, then
    <a for=list>remove</a> <var>listener</var> from <var>event</var>'s {{Event/currentTarget}}
@@ -10051,6 +10054,7 @@ Mark Miller,
 Martijn van der Ven,
 Mats Palmgren,
 Mounir Lamouri,
+Michael Stramel,
 Michael™ Smith,
 Mike Champion,
 Mike Taylor,